Although seismic tomography is currently the mainstay of global seismic imaging, the large-scale deployment of portable instruments to be conducted as the USArray component of Earthscope over the next decade will allow much higher resolution imaging of the solid earth using migration/inversion methods similar to those used in petroleum exploration. Direct wavefield imaging in solid earth structural seismology has been uncommon in comparison to practices in exploration seismology, generally due to the large separation between seismic stations. With the development of portable observatory quality broadband (0.01–20 Hz) seismographs and acquisition of modest numbers of them for the PASSCAL instrument pool...